diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index 0d648ba..b9708343 100644
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -3698,7 +3698,7 @@
 
     if (o->tls_server)
     {
-        if (streq(o->dh_file, "none"))
+        if (o->dh_file && streq(o->dh_file, "none"))
         {
             o->dh_file = NULL;
         }